Work supporting roll for polishing machines



April 26, I938. A. J. SANDORFF I 2,115,217-

WORK SUPPORTING ROLL FOR POLISHING MACHINES Filed Dec. 18, 1955 INVEN T OR.

.A TTORNEYS.

Patented Apr. 26, 1938 Alfred J. Sandorl f, Niagara Falls, N. Y., assignor to General Abrasive Company, Inc., a corporation of New York Application December 18, 1935, Serial No. 55,118

3 Claims.

This invention relates to polishing machines for polishing thin metal sheets, and more particularly to a method of polishing such sheets and to improved constructions of the polishing wheel and the feed roll for use in such machines.

A polishing tool of the type heretofore used for such purposes is not flexible during the polishing operation. On account of this action of the wheel its operating face is not permitted to become accommodated to any of the surface imperfections or irregularities of the'work sheet during polishing, hence, it has been found necessary with the prior polishing, wheels to make many passes of the work back and forth under the wheel during the polishing operation until the superficial high portions of the work have become polished down to substantially the general level of the depressed areas thereof before the surface of the final sheet could be provided with a satisfactory and uniform polish.

It is accordingly an object of the invention to overcome such prior difiiculties and to provide a simple, emcient and improved method of polishing thin metal sheets having various conditions of surface texture.

Another object of the invention is the provision of means whereby metal sheets may be polished on one of the surfaces irrespective of any irregular surface effects therein.

A further object of the invention is to provide an improved supporting body for the work sheet to be polished which will enable the polishing wheel to reproduce on the work a polished surface irrespective of the contour and texture of the original surface of the work.

With these and other objects in view, the invention consists in the steps of the method and of certain novel features of construction, as will be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is a partial diagrammatic view, in elevation, illustrating a polishing machine embodying my invention inoperative relationship with respect to a sheet of work;

Fig. 2 is a diagrammatic top plan view of the polishing apparatus shown in Figure 1;

Fig. 3 is a fragmentary cross-sectional view of a portion of a feed roll formed in accordance with my invention;

Fig. 4 is a fragmentary longitudinal sectional view of the roll structure shown in Figure 3;

Fig. 5 is a fragmentary longitudinal view, in section, of an abrasive polishing wheel embodying a feature of the invention;

that it will permit deformation of the irregular surface portions carried by the surface of the sheet which is being acted upon by the polishing 1 wheel during its passage thereunder. I therefore propose to provide a yieldable supporting member for the metal sheet and preferably a roll having a resilient or yieldable outer surface portion which will contact with the under surface of the sheet of work, and to accomplish the polishing operation on the upper face of the sheet by means of a hard, substantially inflexible abrasive polishing body or roll which is so arranged with respect to the lower supporting roll as to contact with the upper surface of the sheet to polish the same as the sheet is continuously and progressively fed thereunder. Thus, the sheet is so supp rted during its passage beneath the polishing roll that the pressure incident'to the polishing operation causes temporary deformation of those irregularities on its upper surface to force them into contact with the polishing wheel while any thick places in the work are depressed into the resilient outer covering of the lower supporting roll as the sheet passes between the rolls.

With reference to the drawing, one specific embodiment of the invention shown in Figures 1 to 5, inclusive, comprises a polishing wheel l0 rotatably mounted on a shaft l2, the wheel being arranged in contact with one side of a sheet of work l3 which in turn is supported on its under side by supporting roll or drum ll of a yieldable construction and mounted for rotation on a shaft IS, the sheet being continuously and progressively advanced between the rolls and fed therethrough at the speed desired. The rolls l0 and M, respectively, are mounted to rotate in opposite directions, the polishing roll Ill being suitably driven at high speed from any appropriate source of power while the lower work supporting roll I4 is adapted to travel at a slow speed whereby its yieldable characteristic may be maintained. A suitable conduit I6 is provided to be used in conjunction with the polishing wheel I0 so as to discharge a fluid coolant, such as water, from the nozzles l1 into the polishing zone of the polishing wheel and the work. The work sheet l3 may be fed either by the feed rolls l8, as shown in Figure 1, which are mounted on one side of the work surface and the rolls I! on the other side thereof or the supporting roll l4 may be utilized to act upon the under side of the sheet 13 to impart movement of the sheet between the rolls [0 and I4, respectively.

The polishing wheel I!) may be of any suitable rigid and substantially non-yieldable construction, but as illustrated in the drawing, Figure 5, it preferably consists of a hard external outer layer or portion 20 forming an abrasive sleeve on the drum and composed of a mixture of abrasive grains and hard vulcanized rubber integrally uniting the grains together, the layer 2|! being secured by vulcanization to an inner fabric sleeve 2|. The sleeves 20 and 2| may be mounted directly on a solid central drum 22 or they may be affixed to a suitable hollow metal cylinder which in'turn may be removably mounted upon and secured to the metal drum 22. If desired, the polishing wheel surface may be provided with a coolant conductive groove, or the wheel may be formed with a relatively smooth and substantially continuous polishing surface. If the former construction, the sleeve may be bound on the drum 22 by means of a suitable binding wire 23 wound in the coolant conducting groove. The ends of the wire may be secured in anysuitable manner, as by a clamping screw 24. This abrasive portion 20 of the polishing wheel may be made by' various methods, the grooved sleeve being formed with an inner fabric sleeve which is first prepared by winding a strip of fabric around a metal cylinder after which the rubber and abrasive element is applied thereto either as a wound strip of the extruded rubber and abrasive mixture, or I may employ a fictile or plastic mixture of the rubber and abrasive grains which is molded in situ around the fabric sleeve, this latter method being more fully described and claimed in my co-pending application, Serial No. 55,115, filed December 18, 1935. The abrasive grains employed may be of any suitable grit size and are selected in accordance withthe polishing properties desired in the finished wheel and the phsyical characteristics of the sheet material to be polished.

In order that the surface irregularities of the metal sheet may be deformed momentarily into the surface of the lower roll I during the polishing operation, I have constructed the roll M which supports the sheet with a deformable outer covering layer 25 composed of a resilient or yieldable material, such as soft vulcanized rubber, leather or cork, the layer 25 being aflixed to an inner fabric sleeve 26 and the whole structure being either directly mounted upon or removably secured to a central drum or support 28. If soft rubber is preferred for the layer 25 I may make this portion by either wrapping 'a strip of fabric around the metal center' and winding sheets of soft rubber about the fabric layer to build it up tothe desired thickness, or by molding a plastic rubber composition in situ about the fabric sleeve; and in both cases, the rubber subse quently vulcanized to form soft, yulcanized rubber.

If desired, a modified construction as shown in Figure 6 may be used in which the fabric sleeve 26, shown in Figure 3, between the outer resilient layer 25 and the central drum 28 is eliminated, and the soft rubber outer layer I0 vulcanized directly to the central drum 28. In this case, the

surface of the drum maybe preliminarily treated in accordance with any practice in the art, such as brass platin prior to forming the rubber layer 30 thereon in order to provide good adhesion of the-rubber to metal surfaces after vulcanizing the rubber.

In Figure 7, I have illustrated another modified construction of work supporting roll 14 which is feasible and incorporating a yieldable outer work 7 engaging portion. In this construction, the soft rubber outer covering layer 33 is vulcanized directly to a metal sleeve 34 after which the entire sleeve structure may be mounted in any suitable manner on the drum 28 for rotation therewith. The sleeve 34 may likewise be suitably treated, as bybrass plating its outer surface, in order that the rubber layer 33 will firmly stick thereto after vulcanization of the rubber.

It will now be apparent that my invention provides an improved mode of polishing thin metal sheets, since the present arrangement is not one which is dependent upon any yieldability of the structure of the polishing'element as heretofore proposed, but it now transfers the yieldable feature to the lower supporting roll for the sheet whereby the surface irregularities present upon the upper face of the sheet are pressed into the yieldable surface layer of the lower roll as they pass under the polishing wheeliand the surface contacted thereby is polished without permanent change in the original irregular surface of th sheet.

The foregoing description is directed solely towards theconstruction illustrated, but I desire it to be understood that I reserve the privilege of resorting to all the mechanical changes to which the device is susceptible the invention being defined and limited only by the terms of the appended claims.

I claim:

1. In a machine for polishing thin metal sheets, a work support roll therefor comprising a central cylindrical support provided with an outer work engaging portion in the form of a sleeve consisting of a layer of cork. 1

2. In a machine for polishing thin metal sheets,

a rigid polishing wheel, feed rolls arranged at opposite sides of the axis of said polishing wheel, and a' work support roll positioned between the feed rolls and beneath said polishing wheel, said support roll having an outer work engaging portion comprising a thick layer of cork which is adapted to yield when in contact against the bottom face of the sheet being polished and during its travel between said support roll and the polishing wheel to cause an unbroken line of contact between the work surface of thesheetand the polishing wheel.

3. In a machine for polishing thin metal sheets, a work support roll therefor comprising a central cylindrical support, a 'layer of fabric secured thereon, and an outer work-engaging portion comprising a thick layer of cork superimposed over said fabric layer and integrally united thereto,

, said outer layer of cork being adapted to yleld I man J. sAnnoRrr'. 

